Comparison among Various Thermal and Vibration Loadings as well as the Combined Test for Flip Chip Ball Grid Array Components

• Main Authors: Yang-Sin Li, 李洋欣
• Other Authors: 陳永樹
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/29635936501667423762

碩士 === 元智大學 === 機械工程學系 === 100 === Abstract The electronic devices such as those used in automotive or avionic industries, all subjected to vibration and thermal environmental loadings. These electronics were tested for their reliabilities with thermal and vibration test conducted separately in the past. These kinds of test were considered as not precise enough since they didn’t consider the mutual effects between these two loadings. Thanks to the development of Highly Accelerated Life Test (HALT) test machine, it is possible to conduct test closer to the real world applications by combining both thermal and vibration test simultaneously. This study focuses on examining the resulting stresses of the most vulnerable to damage corner solder ball of today’s sophisticated flip chip ball grid array components (FCBGA) through a series of tests including thermal cycling, vibration, and HALT tests. Meanwhile, the finite element analysis (FEA) with the commercial ANSYS software was also performed for all the foregoing test conditions. It is then feasible to investigate the coupling effects between individual thermal and vibration tests by checking with results from the HALT test. The results showed that if conducting vibration test under the temperature other than room temperature, the generated thermal stress will cause the dynamic properties of the test vehicle as well as the Young's modulus of the solder balls be changed. Similar results were verified though the FEA by finding the thermal stress firstly, and put them as an initial stress on a pre-stressed model to compare with the experimental data. When we add 30Grms vibration into -55~150℃thermal cycling test ,it adds another 170 μstrain(about 15% more strain and can’t be ignored. )Both of these two methods were then varied for the test temperature to explore the effects on the vibration testing results. It was found that with the increase of temperature, the natural frequency also increases too. However, with elevated temperature that softens the solder balls, the observation then differs a bit. Through this study, some of the unexplored data in the dynamic performance and life of the today’s advanced electronic components under combined dynamic loading environments were revealed. The corresponding results were helpful in improving the life estimation accuracy of electronic products. Keywords: FCBGA, HALT, Life, Reliability, Thermal Cycling, Vibration